Solve 1/f=1/a+1/b for f

Mathematics · High School · Mon Jan 18 2021

Answered on

Given the numerical equation:

1/f = 1/a + 1/b

Solve for f.

Solution:

In order to solve for f, we first need to add 1/a + 1/b, this can be done by having a denominator of ab, and a numberator of a + b.

1/a + 1/b = (b + a)/ab

1/f = (b + a)/ab

multiply f on both sides of the equation to cancel out 1/f.

a = f (b + a) /ab

Multiply the reciprocal of (b + a)/ab which is ab/(b + a) to cancel out, and find the value of x.

ab/(b + a) = f( b + a)/ab (ab/(b + a))

f = ab/(b + a)

Final answer:

f = ab/(b + a)